Towards a transgenic model of Huntington's disease in a non-human primate

Non-human primates are valuable for modelling human disorders and for developing therapeutic strategies; however, little work has been reported in establishing transgenic non-human primate models of human diseases. Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder characterized by motor impairment, cognitive deterioration and psychiatric disturbances followed by death within 10-15 years of the onset of the symptoms. HD is caused by the expansion of cytosine-adenine-guanine (CAG, translated into glutamine) trinucleotide repeats in the first exon of the human huntingtin (HTT) gene. Mutant HTT with expanded polyglutamine (polyQ) is widely expressed in the brain and peripheral tissues, but causes selective neurodegeneration that is most prominent in the striatum and cortex of the brain. Although rodent models of HD have been developed, these models do not satisfactorily parallel the brain changes and behavioural features observed in HD patients. Because of the close physiological, neurological and genetic similarities between humans and higher primates, monkeys can serve as very useful models for understanding human physiology and diseases. Here we report our progress in developing a transgenic model of HD in a rhesus macaque that expresses polyglutamine-expanded HTT. Hallmark features of HD, including nuclear inclusions and neuropil aggregates, were observed in the brains of the HD transgenic monkeys. Additionally, the transgenic monkeys showed important clinical features of HD, including dystonia and chorea. A transgenic HD monkey model may open the way to understanding the underlying biology of HD better, and to the development of potential therapies. Moreover, our data suggest that it will be feasible to generate valuable non-human primate models of HD and possibly other human genetic diseases.     

Resveratrol improves health and survival of mice on a high-calorie diet

Resveratrol (3,5,4'-trihydroxystilbene) extends the lifespan of diverse species including Saccharomyces cerevisiae, Caenorhabditis elegans and Drosophila melanogaster. In these organisms, lifespan extension is dependent on Sir2, a conserved deacetylase proposed to underlie the beneficial effects of caloric restriction. Here we show that resveratrol shifts the physiology of middle-aged mice on a high-calorie diet towards that of mice on a standard diet and significantly increases their survival. Resveratrol produces changes associated with longer lifespan, including increased insulin sensitivity, reduced insulin-like growth factor-1 (IGF-I) levels, increased AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor-gamma coactivator 1alpha (PGC-1alpha) activity, increased mitochondrial number, and improved motor function. Parametric analysis of gene set enrichment revealed that resveratrol opposed the effects of the high-calorie diet in 144 out of 153 significantly altered pathways. These data show that improving general health in mammals using small molecules is an attainable goal, and point to new approaches for treating obesity-related disorders and diseases of ageing.     

Absence of effects of Sir2 overexpression on lifespan in C. elegans and Drosophila

Overexpression of sirtuins (NAD(+)-dependent protein deacetylases) has been reported to increase lifespan in budding yeast (Saccharomyces cerevisiae), Caenorhabditis elegans and Drosophila melanogaster. Studies of the effects of genes on ageing are vulnerable to confounding effects of genetic background. Here we re-examined the reported effects of sirtuin overexpression on ageing and found that standardization of genetic background and the use of appropriate controls abolished the apparent effects in both C. elegans and Drosophila. In C. elegans, outcrossing of a line with high-level sir-2.1 overexpression abrogated the longevity increase, but did not abrogate sir-2.1 overexpression. Instead, longevity co-segregated with a second-site mutation affecting sensory neurons. Outcrossing of a line with low-copy-number sir-2.1 overexpression also abrogated longevity. A Drosophila strain with ubiquitous overexpression of dSir2 using the UAS-GAL4 system was long-lived relative to wild-type controls, as previously reported, but was not long-lived relative to the appropriate transgenic controls, and nor was a new line with stronger overexpression of dSir2. These findings underscore the importance of controlling for genetic background and for the mutagenic effects of transgene insertions in studies of genetic effects on lifespan. The life-extending effect of dietary restriction on ageing in Drosophila has also been reported to be dSir2 dependent. We found that dietary restriction increased fly lifespan independently of dSir2. Our findings do not rule out a role for sirtuins in determination of metazoan lifespan, but they do cast doubt on the robustness of the previously reported effects of sirtuins on lifespan in C. elegans and Drosophila.     

Vaccine protection against acquisition of neutralization-resistant SIV challenges in rhesus monkeys

Preclinical studies of human immunodeficiency virus type 1 (HIV-1) vaccine candidates have typically shown post-infection virological control, but protection against acquisition of infection has previously only been reported against neutralization-sensitive virus challenges. Here we demonstrate vaccine protection against acquisition of fully heterologous, neutralization-resistant simian immunodeficiency virus (SIV) challenges in rhesus monkeys. Adenovirus/poxvirus and adenovirus/adenovirus-vector-based vaccines expressing SIV(SME543) Gag, Pol and Env antigens resulted in an 80% or greater reduction in the per-exposure probability of infection against repetitive, intrarectal SIV(MAC251) challenges in rhesus monkeys. Protection against acquisition of infection showed distinct immunological correlates compared with post-infection virological control and required the inclusion of Env in the vaccine regimen. These data demonstrate the proof-of-concept that optimized HIV-1 vaccine candidates can block acquisition of stringent, heterologous, neutralization-resistant virus challenges in rhesus monkeys.     

Lifespan: catch-up growth and obesity in male mice

Poor fetal growth is linked with long-term detrimental effects on health in adulthood. Here we investigate whether the lifespan of male mice is affected by their growth rate when they were suckling and find that limiting growth during that period not only increases longevity but also protects against the life-shortening effect of an obesity-inducing diet later on. By contrast, we find that lifespan is considerably shortened if the postnatal period of growth is accelerated to make up for reduced growth in utero, and that, in addition, these mice are susceptible to the adverse effects on longevity of an obesity-inducing diet after weaning.     

太行山猕猴动脉血压的研究

本文报道了62例太行山猕猴的动脉血压测定结果。分别比较了麻醉状态下与非麻醉状态下的动脉血压值,发现前者低于后者;而在麻醉状态下,雌雄猕猴之间的动脉血压差异显著;并随着猕猴年龄的增长,血压逐渐升高。     

猕猴从幼年到老年的卵巢组织学变化

摘要:目的 观察猕猴的卵巢组织从幼年到老年的变化情况,探索猕猴的卵巢随着年龄增长发生变化的机制,为卵巢衰老的研究提供组织学参考。 方法 (1)筛选幼年猕猴 3 只,青年猕猴 3 只,老年猕猴 3 只。 ( 2) 安乐死处理猕猴,取卵巢组织,电子天平称质量并拍照,横向切成 4 份,置于 4%多聚甲醛固定。 (3) HE 染色观察卵巢组织各级卵泡与结构变化;Masson 染色观察卵巢组织纤维化程度;Tunel 染色统计分析卵巢细胞的凋亡率;免疫组织化学染色统计血管个数。 结果 (1)幼年猕猴的卵巢脏器指数与青年猕猴的无显著差异,都高于老年猕猴的卵巢脏器指数。(2)幼年与青年猕猴的卵巢组织中可见原始、初级、次级,成熟卵泡;老年猕猴的卵巢局部只见闭锁卵泡,大部分被脂肪组织填充。 (3)幼年猕猴的卵巢纤维化程度高于青年猕猴,老年猕猴纤维化程度最高。 ( 4) 幼年猕猴卵巢细胞凋亡率与青年猕猴的无显著差异,都显著低于老年猕猴。 (5)幼年猕猴血管个数最多,青年猕猴多于高于老年猕猴。 结论 随着年龄增长,猕猴卵巢组织中卵泡数量逐渐减少、髓质被大量脂肪组织填充、间质排列散乱,这一生物学过程与卵巢纤维化程度增强、卵巢细胞凋亡率增加、血管个数减少相关。     

太行山猕猴呼吸频率的研究

本文对93例健康的太行山猕猴呼吸频率进行了分析。结果表明:随着年龄的增长太行山猕猴的呼吸频率在一定范围内呈下降趋势;在同一年龄组及样本中,不同性别之间的呼吸频率无显著差别;太行山猕猴的呼吸频率与国外和我国南方猕猴之间差异明显;非麻醉猕猴的呼吸频率明显高于麻醉猴的呼吸频率。     

Lateral habenula as a source of negative reward signals in dopamine neurons

Midbrain dopamine neurons are key components of the brain's reward system, which is thought to guide reward-seeking behaviours. Although recent studies have shown how dopamine neurons respond to rewards and sensory stimuli predicting reward, it is unclear which parts of the brain provide dopamine neurons with signals necessary for these actions. Here we show that the primate lateral habenula, part of the structure called the epithalamus, is a major candidate for a source of negative reward-related signals in dopamine neurons. We recorded the activity of habenula neurons and dopamine neurons while rhesus monkeys were performing a visually guided saccade task with positionally biased reward outcomes. Many habenula neurons were excited by a no-reward-predicting target and inhibited by a reward-predicting target. In contrast, dopamine neurons were excited and inhibited by reward-predicting and no-reward-predicting targets, respectively. Each time the rewarded and unrewarded positions were reversed, both habenula and dopamine neurons reversed their responses as the bias in saccade latency reversed. In unrewarded trials, the excitation of habenula neurons started earlier than the inhibition of dopamine neurons. Furthermore, weak electrical stimulation of the lateral habenula elicited strong inhibitions in dopamine neurons. These results suggest that the inhibitory input from the lateral habenula plays an important role in determining the reward-related activity of dopamine neurons.     

Stimulation of haematopoiesis in primates by continuous infusion of recombinant human GM-CSF

Certain proteins are known to play an important part in the proliferation, differentiation and functional activation of haematopoietic progenitor cells in vitro. These proteins include erythropoietin and various colony-stimulating factors (CSFs), one of which is granulocyte-macrophage colony-stimulating factor (GM-CSF). Recently, both murine and human GM-CSF have been purified to homogeneity and complementary DNAs encoding them have been cloned. Although the in vitro activity of recombinant human GM-CSF has been investigated intensively, little is known about the functional activity of this protein in vivo. There is strong evidence that colony-stimulating activities produced by various human and murine tumour tissues and cell lines can stimulate granulopoiesis in mice, as can human urinary extracts. A partially purified preparation of human urinary colony-stimulating factor, however, proved only marginally effective in stimulating granulopoiesis in humans. All these studies suffer from the lack of a homogeneous preparation of colony-stimulating factor. It has recently been shown that recombinant murine multi-CSF or interleukin-3 can stimulate haematopoiesis in mice in vivo. Large-scale production of recombinant human GM-CSF now permits us to examine its effects in vivo using a primate model. We find that the continuous infusion of GM-CSF in healthy monkeys rapidly elicits a dramatic leukocytosis and a substantial reticulocytosis. A similar effect has been observed in one pancytopenic, immunodeficient rhesus macaque. These results suggest that GM-CSF could prove useful in several clinical situations.     

Small molecule activators of SIRT1 as therapeutics for the treatment of type 2 diabetes

Calorie restriction extends lifespan and produces a metabolic profile desirable for treating diseases of ageing such as type 2 diabetes. SIRT1, an NAD+-dependent deacetylase, is a principal modulator of pathways downstream of calorie restriction that produce beneficial effects on glucose homeostasis and insulin sensitivity. Resveratrol, a polyphenolic SIRT1 activator, mimics the anti-ageing effects of calorie restriction in lower organisms and in mice fed a high-fat diet ameliorates insulin resistance, increases mitochondrial content, and prolongs survival. Here we describe the identification and characterization of small molecule activators of SIRT1 that are structurally unrelated to, and 1,000-fold more potent than, resveratrol. These compounds bind to the SIRT1 enzyme-peptide substrate complex at an allosteric site amino-terminal to the catalytic domain and lower the Michaelis constant for acetylated substrates. In diet-induced obese and genetically obese mice, these compounds improve insulin sensitivity, lower plasma glucose, and increase mitochondrial capacity. In Zucker fa/fa rats, hyperinsulinaemic-euglycaemic clamp studies demonstrate that SIRT1 activators improve whole-body glucose homeostasis and insulin sensitivity in adipose tissue, skeletal muscle and liver. Thus, SIRT1 activation is a promising new therapeutic approach for treating diseases of ageing such as type 2 diabetes.     

制备偏侧帕金森病猴模型的术前准备及术后护理

摘要: 目的 概述偏侧帕金森病猴模型术前准备中需要注意的事项及术后护理心得。方法 选取猕猴 10 只,经股 动脉介入方法对一侧颈内动脉注射 1-甲基-4-苯基-1 ,2 ,3 ,6-四氢吡啶( MPTP) ,建立偏侧性帕金森病( PD) 猴模 型,在术前、术后积极实施相关护理措施。重点涉及到驯养技巧、手术前后的常规护理、并发症防治及饲养管理等 方面的内容。结果 所有猕猴均成功注药,术后生存率为 80% 。结论 成熟的手术方法对模型制作固然重要,精心的护理和完善的准备却是保障动物生命安全以及术后迅速恢复的关键环节。     

健康恒河猴心电图研究

目的研究健康恒河猴在清醒状态下的心电图特点。方法选择60只2-3岁健康恒河猴,体重2-3．5kg; 雌雄各30只;在环境安静、动物清醒状态下,测定I、Ⅱ、Ⅲ、aVR、aVL、aVF六个导联的心电图变化,并计算平均心 率,平均心电轴,P波、QRs波群和T波的振幅,PR间期、QT问期等指标。结果60只恒河猴均为窭性心律,并发 现在肢体Ⅱ导联中,P波均为向上直立波,Ⅱ、Ⅲ、aVF导联中大部分恒河猴没有s波,aVR导联中大部分恒河猴没 有Q波。雌性恒河猴R波电压平均值明显高于雄性恒河猴平均值(P<0．005)。恒河猴P波较尖,QRs波群多样 化,QT问期的K值范围是0．298 4-0．030,ST段位于等电位线,T波以圆滑为主,Ⅱ导联中绝大部分为直立。结论 此研究建立了恒河猴心电图相关基础数据,为相关的研究提供了参考。     

Calorie restriction extends Saccharomyces cerevisiae lifespan by increasing respiration

Calorie restriction (CR) extends lifespan in a wide spectrum of organisms and is the only regimen known to lengthen the lifespan of mammals. We established a model of CR in budding yeast Saccharomyces cerevisiae. In this system, lifespan can be extended by limiting glucose or by reducing the activity of the glucose-sensing cyclic-AMP-dependent kinase (PKA). Lifespan extension in a mutant with reduced PKA activity requires Sir2 and NAD (nicotinamide adenine dinucleotide). In this study we explore how CR activates Sir2 to extend lifespan. Here we show that the shunting of carbon metabolism toward the mitochondrial tricarboxylic acid cycle and the concomitant increase in respiration play a central part in this process. We discuss how this metabolic strategy may apply to CR in animals.     

中国恒河猴MHC I型部分等位基因的分析

摘要：目的对中国恒河猴主要组织相容性复合体(MHC)l型部分基因进行携带情况调查与分析。方法采用序 列特异性引物(PCR—SSP)分型方法对华南灵长类动物研究中心繁殖的30只谱系清晰的中国恒河猴(Macaca mulatta)的32个MHC I型分子位点进行检测。结果采用的32对引物中,中国恒河猴可检出携带23个MHC—I等 位基因,但基因携带频率存在很大的差异,由3．57％至82．14％不等。结合遗传谱系分析,判断A1·21和b．2睾05 之间以及B·04和B·30之间可能就是连锁的。结论中国恒河猴携带能控制病毒复制的MHC I型基因位点的 频率较高,其基因携带频率与已发表的印度恒河猴携带频率存在明显差异。本研究为促进中国恒河猴在AIDS研 究中的应用,以及为建立携带特定MHC I基因实验猴小种群提供了依据。     

太行猕猴头毛中6种微量元素含量测定初报

本文对25只正常成年太行猕猴头毛中6种微量元素含量进行了测定。雌猴与雄猴间6种微量元素均无显著性差异,孕猴与非孕猴间除Cu外,也无显著性意义。饲养在不同地区的太行猕猴Cu、Cr有显著性差异,而Pb含量有极显著差异。猕猴头毛与人发比较Zn、Cu含量相接近,而Fe、Mn含量比人高达几倍到数十倍。     

一例老年恒河猴消化系统疾病诊断

摘要:本实验室人工饲养的一只老年恒河猴出现以腹泻、排脓样便、消瘦为主要体症的急性疾病。为研究老年恒河 猴消化器官病变的发生情况并进行诊断,本实验采用临床体征结合常规HE 染色对其消化系统进行组织学观察,结 果发现恒河猴的消化系统组织存在不同程度的病变,包括各种炎性细胞浸润,杯状细胞减少及黏液分泌减少,消化 道黏膜的变性、坏死,消化腺的萎缩等,诊断该老龄猴为生理性衰老。     

Immune control of an SIV challenge by a T-cell-based vaccine in rhesus monkeys

A recombinant adenovirus serotype 5 (rAd5) vector-based vaccine for HIV-1 has recently failed in a phase 2b efficacy study in humans. Consistent with these results, preclinical studies have demonstrated that rAd5 vectors expressing simian immunodeficiency virus (SIV) Gag failed to reduce peak or setpoint viral loads after SIV challenge of rhesus monkeys (Macaca mulatta) that lacked the protective MHC class I allele Mamu-A*01 (ref. 3). Here we show that an improved T-cell-based vaccine regimen using two serologically distinct adenovirus vectors afforded substantially improved protective efficacy in this challenge model. In particular, a heterologous rAd26 prime/rAd5 boost vaccine regimen expressing SIV Gag elicited cellular immune responses with augmented magnitude, breadth and polyfunctionality as compared with the homologous rAd5 regimen. After SIV(MAC251) challenge, monkeys vaccinated with the rAd26/rAd5 regimen showed a 1.4 log reduction of peak and a 2.4 log reduction of setpoint viral loads as well as decreased AIDS-related mortality as compared with control animals. These data demonstrate that durable partial immune control of a pathogenic SIV challenge for more than 500 days can be achieved by a T-cell-based vaccine in Mamu-A*01-negative rhesus monkeys in the absence of a homologous Env antigen. These findings have important implications for the development of next-generation T-cell-based vaccine candidates for HIV-1.     

恒河猴B病毒血清抗体流行病学调查

目的摸清B病毒(BV)感染现状,从而有效降低BV在恒河猴群中的感染率。方法采用ELISA方法对恒河猴血清进行抗体检测。结果检测样品629份,其中350份呈BV抗体阳性,10份血清呈BV抗体可疑,其余血清为抗体阴性。结论种猴(≥11周岁)BV感染率89%;青年猴(3~10周岁)BV感染率39.2%;幼龄猴(≤2周岁)BV感染率7.6%。随着年龄的增长,恒河猴群中BV感染率越高。